Symbiont-dependent-development
Guides
Anasa tristis
Squash Bug
Anasa tristis is a significant agricultural pest native to North America, specializing in cucurbit crops including squash, pumpkins, and zucchini. Adults are greyish-brown, flattened insects approximately 1.5 cm long with distinctive alternating brown and gold spots along the abdominal margin. The species is a phloem-feeding sap sucker that physically damages plant xylem and leaves, causing wilting, darkening, and death. It also vectors the bacterial pathogen Serratia marcescens, which causes cucurbit yellow vine disease—a condition particularly prevalent in Oklahoma and Texas but spreading to other regions. When disturbed, adults emit an unpleasant odor.